Rerounding mechanism for a rotary domer

ABSTRACT

A conventional rotary domer, or base-forming machine, having a spider for carrying a number of female dies and a number of articles to be formed by said female dies, said spider being secured to a shaft, and a male die-carrying spider also secured to said shaft and having one die for each female die being carried by said first-named spider, and having means for reciprocating the respective male dies during a partial revolution of the shaft, is provided with a bushing telescopingly embracing each male die, and separate means for reciprocating said bushings. The separate means is arranged to advance each bushing before the respective male die advances, to reround the article to be formed and to align it properly with the respective male and female dies. The several bushings may be retracted after the respective male dies have entered the respective articles and before the respective males have completed their advance, or they may be retracted concurrently with the respective male dies, or they may be retracted after the respective male dies have been retracted, and thus serve as strippers for stripping the articles from the respective male dies.

United States Patent [72] Inventor Elton G. Kaminski Sidney, Ohio [21] App1.No. 3,737 [22] Filed Jan. 19, 1970 [45] Patented Nov. 9, 1971 [73] Assignee The Stolle Corporation Sidney, Ohio [54] REROUNDING MECHANISM FOR A ROTARY DOMER 7 Claims, 4 Drawing Figs.

[52] U.S. Cl 113/7 R, 72/94 [51] lnt.C1 ..B21d 51/26 [50] Field of Search 113/7 R. 120 R. 120 H; 72/94, 348. 349

[56] References Cited UNITED STATES PATENTS 3,548,769 12/1970 Windstrup 113/7 R 3,295,352 1/1967 Middlestadt 113/120 H 3.402.591 9/1968 Maeder 113/120 H 3.446.167 5/1969 Armbruster 1 13/7 R 3,491,574 1/1970 Helrigel et a1. 72/348 Primary Examiner-Charles W. Lanham Assistant Examiner-Michael J. Keenan Allorney-Melville. Strasser. Foster & Hoffman ABSTRACT: A conventional rotary domer. or base-forming machine, having a spider for carrying a number of female dies and a number ofarticles to be formed by said female dies. said spider being secured to a shaft. and a male die-carrying spider also secured to said shaft and having one die for each female die being carried by said first-named spider. and having means for reciprocating the respective male dies during a partial revolution of the shaft. is provided with a bushing telescopingly embracing each male die. and separate means for reciprocating said bushings. The separate means is arranged to advance each bushing before the respective male die advances. to reround the article to be formed and to align it properly with the respective male and female dies. The several bushings may be retracted after the respective male dies have entered the respective articles and before the respective males have completed their advance. or they may be retracted concurrently with the respective male dies, or they may be retracted after the respective male dies have been retracted. and thus serve as strippers for stripping the articles from the respective male dies.

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Fig 3 E lfon G. Kaminski ,BY adda, aim W ATTORNEYS REROUNDING MECHANISM FOR A ROTARY DOMER BRIEF SUMMARY OF THE INVENTION In some manufacturing operations, as for example the manufacture of open-end cans or containers, there is carried out what is known as a doming or base-forming operation. Such operations are generally carried out on machines known as rotary domers or base-forming machines. Such machines are used for example for trimming the ends of containers, for flanging operations and the like, in addition to base-forming operations.

As a result of previous operations conducted on the workpieces, they may have become out of round" or the edges may have been bent or deformed. In cases where a die which fits closely within the container must enter the container, it is very necessary that the edges of the container not interfere with the entrance of the die as a result of being out of round or deformed.

According to the present invention, a conventional doming machine is provided with a rerounding apparatus which restores the original circular configuration of the can or the like, so that the male die can enter it without interference.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view of a more or less conventional doming machine or base-forming machine with parts in section.

FIG. 2 is a fragmentary cross-sectional view taken on the line 2-2 of FIG. 1.

FIG. 3 is a similar view taken on the line 3-3 ofFIG. 1.

FIG. 4 is an elevational view with parts in section showing the spider which carries the female die and the relationship between it and the male die, the rerounding bushing and the article being operated upon.

DETAILED DESCRIPTION Basically, the doming machine comprises a main shaft which is driven at constant speed by mechanism not shown. Secured to the shaft 10 is a spider 11 which carries a number offemale die elements I2.

Also mounted on the shaft 10 is a spider 13 which, as best seen in FIG. 3, is provided with a plurality of partly circular depressions I4 around its periphery. As will be clear from an examination of FIGS. 2 and 3, the spider II in the example shown carries twelve female dies, whereas the spider 13, which may be referred to as a star wheel, is provided with twelve semicircular depressions. These depressions are of a diameter such that the article being operated upon, e.g. a beverage can or the like, may be seated therein. It should also be remarked that for clarity only two diametrically opposite female dies have been shown in FIG. 4 and in FIG. I.

By reference to FIGS. 2 and 3, it will be apparent how the cans or the like are fed to the apparatus. Associated with the star wheel 13 is a lead screw I5 whose thread is of such magnitude that when a can enters the thread it will be conveyed along the axis of the screw as shown in FIG. 3. The cans are fed through a track I6 and are conveyed toward the left, as seen in FIG. 3, by the screw 15. The screw 15 and the star wheel 13 are driven in timed relation so that as a can reaches the position indicated at 16 in FIG. 3, it has entered into one of the semicircular recesses in the star wheel 13. It will be observed that there is a guide ring 17 which extends below the cans as they enter the screw 15 and which extends around the star wheel to a point 18. The ring 17 simply causes the cans 19 to be retained in the pockets in the star wheel as it rotates in the direction of the arrow.

The doming or other operations on the cans are performed during the movement of the cans from the point 16 to the point 18. By reference to FIG. 2, it will be observed that there is a smaller star wheel 20 provided with semicircular recesses or pockets 21 which rotates oppositely to the star wheel 11 and it is provided with a retaining ring 22 similar to the ring 17. It will now be clear that as the cans approach the position indicated at 23 in FIG. 2, they willbe picked up out of the star wheel II and engaged in the star wheel 20 and carried around to the discharge chute 24.

Returning now to FIG. 1, it will be observed that there is a spider 25 secured on the shaft 10 and this spider carries a plurality of punches 26, which in this case are equal in number to the number of female dies and which are aligned with the female dies. Each of the punches is provided with a cam follower 27 and the cam followers of all of the punches ride in a groove 28 in a circular cam which is fixed to the machine frame. It will be clear, therefore, that as the spider 25 and the spider l3 and the shaft 10 all rotate, the cam followers 27 riding in the cam track 28 will cause the punches 26 to reciprocate. The cam track 28 is laid out such that the reciprocation of each punch 26 is completed between the point 16 and the point 18 noted in FIG. 3. Secured to each of the punches 26 is a male die 29.

The parts of the rotary domer thus far described are more or less conventional and no claim to them is made as such.

According to the present invention, there is associated with each male die a rerounding bushing indicated at 30. Each of the rerounding bushings 30 is provided with a cam follower III which rides in a cam track or groove 32 mounted on a cam carrier 33 which initially can be moved in relation to the shaft 10. An arm 34 is secured to the carrier 33 by means of which it may be anchored to the machine frame as at 35 after initial adjustment.

The cam track 32 is so laid out that it moves the rerounding bushing separately from the punch and male die. The cam track may provide for various types of action. For example, the rerounding bushing which is preferably flared, as indicated at 300, may be caused to advance and engage the open end of the can to reround it and then be withdrawn as soon as the punch 29 has entered the can body. Alternatively, the rerounding bushing may simply be permitted to stay in position and be withdrawn concurrently with the punch and male die. As a third alternative, the rerounding bushing may be caused to stay in engagement with the can body while the male die is being withdrawn so as to assist in stripping the can from the die. The particular timing of the withdrawal of the rerounding bushing will depend upon considerations of the particular job being performed.

The operation of the rerounding apparatus in connection with the conventional rotary domer will be clear from the foregoing description. It will be understood that modifications may be made without departing from the spirit of the invention and that therefore no limitations not specifically set forth in the claims is intended or should be implied.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a rotary domer having a main shaft, a first spider secured to said shaft and having equally spaced thereabout a plurality of tubular-article-engaging means and female dies in axial alignment with said article-engaging means, a second spider secured to said shaft and carrying a number of reciprocable male dies in axial alignment with the aforementioned female dies, a first fixed circular cam track extending around said shaft concentrically, a cam follower associated with each of said male dies and in operative engagement with said first track to cause said male dies to reciprocate as said shaft and spiders rotate; a rerounding bushing embracing each of said male dies in telescoping relation, a second fixed circular cam track extending around said shaft and concentric therewith, a cam follower associated with each of said rerounding bushings and in operative engagement with said second track to cause said rerounding bushings to reciprocate as said shaft and spiders rotate, said first track being configured to cause each of said male dies in turn to advance and retract during less than a full revolution of said shaft, and said second track being configured to cause each of said rerounding bushings in turn to advance before its respective male die advances, and to retract during less than a full revolution of said shaft.

2. Apparatus according to claim 1, wherein said second fixed cam has secured to it an anchoring member which is secured to the apparatus in a desired position of adjustment in relation to said shaft.

3. Apparatus according to claim ll, wherein the said first cam track is configured to advance and retract the several male dies in about five/eighths of a revolution of the shaft the remaining portion of the full revolution being a dwell.

4. Apparatus according to claim 1, wherein said second cam track is configured to retract said several rerounding bushings after the respective male dies have entered tubular articles engaged in said tubular-article-engaging means.

5. Apparatus according to claim 1, wherein said second cam track is configured to retract said several rerounding bushings before the respective male dies have completed their advance.

6. Apparatus according to claim A, wherein said second cam track is configured to retract said several rerounding bushings at the same time as the respective male dies are retracted.

7. Apparatus according to claim 1, wherein said second cam track is configured to retract said several reroundings bushings after the respective male dies are retracted. 

1. In a rotary domer having a main shaft, a first spider secured to said shaft and having equally spaced thereabout a plurality of tubular-article-engaging means and female dies in axial alignment with said article-engaging means, a second spider secured to said shaft and carrying a number of reciprocable male dies in axial alignment with the aforementioned female dies, a first fixed circular cam track extending around said shaft concentrically, a cam follower associated with each of said male dies and in operative engagement with said first track to cause said male dies to reciprocate as said shaft and spiders rotate; a rerounding bushing embracing each of said male dies in telescoping relation, a second fixed circular cam track extending around said shaft and concentric therewith, a cam follower associated with each of said rerounding bushings and in operative engagement with said second track to cause said rerounding bushings to reciprocate as said shaft and spiders rotate, said first track being configured to cause each of said male dies in turn to advance and retract during less than a full revolution of said shaft, and said second track being configured to cause each of said rerounding bushings in turn to advance before its respective male die advances, and to retract during less than a full revolution of said shaft.
 2. Apparatus according to claim 1, wherein said second fixed cam has secured to it an anchoring member which is secured to the apparatus in a desired position of adjustment in relation to said shaft.
 3. Apparatus according to claim 1, wherein the said first cam track is configured to advance and retract the several male dies in about five/eighths of a revolution of the shaft, the remaining portion of the full revolution being a dwell.
 4. Apparatus according to claim 1, wherein said second cam track is configured to retract said several rerounding bushings after the respective male dies have entered tubular articles engaged in said tubular-article-engaging means.
 5. Apparatus according to claim 1, wherein said second cam track is configured to retract said several rerounding bushings before the respective male dies have completed their advance.
 6. Apparatus according to claim 1, wherein said second cam track is configured to retract said several rerounding bushings at the same time as the respective male dies are retracted.
 7. Apparatus according to claim 1, wherein said second cam track is configured to retract said several reroundings bushings after the respective male dies are retracted. 